Decolorization of Reactive Red 2 by advanced oxidation processes: Comparative studies of homogeneous and heterogeneous systems

This study investigated the decolorization of the Reactive Red 2 in water using advanced oxidation processes (AOPs): UV/TiO2, UV/SnO2, UV/TiO2+SnO2, O3, O3+MnO2, UV/O3 and UV/O3+TiO2+SnO2. Kinetic analyses indicated that the decolorization rates of Reactive Red 2 could be approximated as pseudo-first-order kinetics for both homogeneous and heterogeneous systems. The decolorization rate at pH 7 exceeded pH 4 and 10 in UV/TiO2 and UV/TiO2+SnO2 systems, respectively. However, the rate constants in the systems (including O3) demonstrated the order of pH 10>pH 7>pH 4. The UV/TiO2+SnO2 and O3+MnO2 systems exhibited a greater decolorization rate than the UV/TiO2 and O3 systems, respectively. Additionally, the promotion of rate depended on pH. The variation of dye concentration influenced the decolorization efficiency of heterogeneous systems more significant than homogeneous systems. Experimental results verified that decolorization and desulfuration occurred at nearly the same rate. Moreover, the decolorization rate constants at pH 7 in various systems followed the order of UV/O3 > or = O3+MnO2 > or = UV/O3+TiO2+SnO2 > O3 > UV/TiO2+SnO2 > or = UV/TiO2 > UV/SnO2.     

Homogeneous catalytic ozonation of C.I. Reactive Red 2 by metallic ions in a bubble column reactor

This study elucidates the decolorization of C.I. Reactive Red 2 (RR2) by homogeneous catalytic ozonation. The effects of pH and catalyst dosage were evaluated in O3/Mn(II), O3/Fe(II), O3/Fe(III), O3/Zn(II), O3/Co(II) and O3/Ni(II) systems. In O3/Mn(II), O3/Fe(II) and O3/Fe(III) systems, increasing the catalyst concentration increased the rate of RR2 decolorization; however, further increasing the catalyst concentration caused no further significant increase. When 0.6 mM catalyst was added, the decolorization rates of O3/Mn(II), O3/Fe(II), O3/Fe(III), O3/Zn(II), O3/Co(II) and O3/Ni(II) systems at pH 2 were 3.295, 1.299, 1.278, 1.015, 0.843 and 0.822 min(-1), respectively. Under all of the experimental conditions, the decolorization efficiency of catalytic ozonation exceeded that of ozonation alone. The decolorization rate markedly exceeds the TOC removal rate in all tested systems. The effect of the radical scavenger on the catalytic ozonation processes suggests that the decolorization reaction in catalytic ozonation systems proceeds by mainly radical-type mechanisms, except in the O3/Mn(II) system.     

Effects of sonication on decolorization of C.I. Reactive Red 198 in UV/ZnO system

This study discusses the effects of ultrasound (US) irradiation on the decolorization of C.I. Reactive Red 198 (RR198) in UV/ZnO system. The influences of ZnO dosage, pH and the addition of NaCl or a radical scavenger were evaluated. The decolorization rate of RR198 increased with the ZnO dosage in 0.1-1g/l and with pH in the UV/ZnO system. US accelerated the decolorization of RR198 in the UV-based system. The enhancement in the presence of NaCl can be attributed to an increase in the partitioning of RR198 upon cavitation implosion in US/ZnO system. At pH 7, the decolorization rate constants of UV/US/ZnO, UV/ZnO, US/ZnO, UV/US and US were 0.0739, 0.0534, 0.0022, 0.0020 and 0.0013 min(-1), respectively. The decolorization rate was effectively inhibited by adding 1-butanol to UV/ZnO and UV/US/ZnO systems, suggesting that the main mechanism of RR198 destruction is chemical oxidation by hydroxyl radicals in the bulk liquid. The experimental results revealed that the UV/US/ZnO system cannot only completely decolorize RR198 but can effectively mineralize RR198.     

Photodegradation of methyl tert-butyl ether (MTBE) by UV/H2O2 and UV/TiO2

Two UV-based advanced oxidation processes (AOPs), UV/H2O2 and UV/TiO2, were tested in batch reactor systems to evaluate the removal efficiencies and optimal conditions for the photodegradation of methyl tert-butyl ether (MTBE). The optimal conditions at an initial MTBE concentration of 1 mM ([MTBE]0=1 mM) were acidic and 15 mM H2O2 in UV/H2O2 system, and pH 3.0 and 2.0 g/l TiO2 in UV/TiO2 suspended slurries system under 254-nm UV irradiation. Under the optimal conditions, MTBE photodegradation during the initial period of 60 min in UV/H2O2 and UV/TiO2 systems reached 98 and 80%, respectively. In both systems, MTBE photodegradation decreased with increasing [MTBE]0. While MTBE photodegradation rates increased with increasing dosage of H2O2 (5-15 mM) and TiO2 (0.5-3 g/l), further increase in the dosage of H2O2 (20 mM) or TiO2 (4 g/l) adversely reduced the MTBE photodegradation. Pseudo first-order kinetics with regard to [MTBE] can be used to describe the MTBE photodegradation in both systems. The pseudo first-order rate constants linearly increased with the increase in the molar ratio of [H2O2]0 to [MTBE]0 in UV/H2O2 system and linearly increased with the decrease in [MTBE]0 in UV/TiO2 system.     

Comparison of several advanced oxidation processes for the decolorization of Reactive Red 120 azo dye in aqueous solution

In this study UV/TiO2, electro-Fenton (EF), wet-air oxidation (WAO), and UV/electro-Fenton (UV/EF) advanced oxidation processes (AOPs) have been applied to degrade Reactive Red 120 (RR120) dye in aqueous solution. The most efficient method on decolorization and mineralization of RR120 was observed to be WAO process. Photocatalytic degradation of RR120 by UV/TiO2 have been studied at different pH values. At pH 3 photocatalytic degradation kinetics of RR120 successfully fitted to Langmuir-Hinshelwood (L-H) kinetics model. The values of second order degradation rate (k") constant and adsorption constant (K) were determined as 4.525 mg L(-1) min(-1) and 0.387 L mg(-1), respectively. Decolorization efficiency observed in the order of WAO > UV/TiO2 = UV/EF > EF while WAO > UV/TiO2 > UV/EF > EF order was observed in TOC removal (mineralization). For all AOPs, it was found that degradation products in reaction mixture can be disposed safely to environment after 90 min treatment.     

Degradation of C.I. Reactive Red 2 (RR2) using ozone-based systems: comparisons of decolorization efficiency and power consumption

This study investigated the decolorization efficiency of C.I. Reactive Red 2 (RR2) in O3, O3/H2O2, O3/Fe3+, O3/H2O2/Fe3+, UV/O3, UV/O3/Fe3+, UV/O3/H2O2 and UV/O3/H2O2/Fe3+ systems at various pHs. The effective energy consumption constants and the electrical energy per order of pollutant removal (EE/O) were also determined. The experimental results indicated that the energy efficiency was highest at [H2O2]0=1000mg/l and [Fe3+]0=25mg/l. Accordingly, the H2O2 and Fe3+ doses in the hybrid ozone- and UV/ozone-based systems were controlled at these values. This work suggests that the dominant reactant in O3, O3/Fe3+ and O3/H2O2 systems was O3 and that in the O3/H2O2/Fe3+ system was H2O2/Fe3+. The experimental results revealed that the combinations of Fe3+ or H2O2/Fe3+ with O3 at pH 4 and of H2O2 or H2O2/Fe3+ with UV/O3 at pH 4 or 7 yielded a higher decolorization rate than O3 and UV/O3, respectively. At pH 4, the EE/O results demonstrated that the UV/O3/H2O2/Fe3+ system reduced 85% of the energy consumption compared with the UV/O3 system. Moreover, the O3/H2O2/Fe3+ system reduced 62% of the energy consumption compared with the O3 system. At pH 7, the EE/O results revealed that the UV/O3/H2O2/Fe3+ system consumed half the energy of the UV/O3 system.     

Decolorization of C.I. Acid Blue 9 solution by UV/Nano-TiO(2), Fenton, Fenton-like, electro-Fenton and electrocoagulation processes: a comparative study

This study makes a comparison between UV/Nano-TiO(2), Fenton, Fenton-like, electro-Fenton (EF) and electrocoagulation (EC) treatment methods to investigate the removal of C.I. Acid Blue 9 (AB9), which was chosen as the model organic contaminant. Results indicated that the decolorization efficiency was in order of Fenton>EC>UV/Nano-TiO(2)>Fenton-like>EF. Desired concentrations of Fe(2+) and H(2)O(2) for the abatement of AB9 in the Fenton-based processes were found to be 10(-4)M and 2 x 10(-3) M, respectively. In the case of UV/Nano-TiO(2) process, we have studied the influence of the basic photocatalytic parameters such as the irradiation time, pH of the solution and amount of TiO(2) nanoparticles on the photocatalytic decolorization efficiency of AB9. Accordingly, it could be stated that the complete removal of color, after selecting desired operational parameters could be achieved in a relatively short time, about 25 min. Our results also revealed that the most effective decomposition of AB9 was observed with 150 mg/l of TiO(2) nanoparticles in acidic condition. The effect of operational parameters including current density, initial pH and time of electrolysis were studied in electrocoagulation process. The results indicated that for a solution of 20 mg/l AB9, almost 98% color were removed, when the pH was about 6, the time of electrolysis was 8 min and the current density was approximately 25 A/m(2) in electrocoagulation process.     

正极材料zLi2MnO3·（1-z）LiNi0.4Mn0.4Co0.2O2的合成与性能

富锂锰过渡金属层状正极材料以其成本低、安全、容量高受到广泛关注,X射线衍射（XRD）和电化学性能测试显示以共沉淀结合煅烧成功合成富锂层状正极材料zLi2MnO3.（1-z）LiMn0.4Ni0.4Co0.2O2（z=0.2,0.4,0.6）。其中z=0.4组分的放电容量达到210mAh/g（2-4.8V,0.05C）,远高于z=0.6组分,而经20个充放电循环的稳定性也优于z=0.2组分。微分容量分析表明z=0.2组分中因Ni/（Co＋Mn）比值较大和Li2MnO3含量较少可能导致其容量逐渐衰减。z=0.6则因所含LiMn0.4Ni0.4Co0.2O2量较少,造成其放电容量较低;z=0.4拥有最佳Li2MnO3及LiMn0.4Ni0.4Co0.2O2组合使其容量和循环性能最好。     

Ba0.8Sr0.2Ti0.5Mn0.5O3纳米晶体的合成及气敏性质研究

采用复合碱媒介法(CHM),在合成BaMnO3和Ba0.5Sr0.5MnO3的基础上,以Sr(NO3)2、BaCO3以及MnO2和TiO2为原料,在200℃、24h的生长条件下,用20%的Sr离子替代20%的Ba离子,用50%的Ti离子替代50%的Mn离子成功合成了Ba0.8Sr0.2Ti0.5Mn0.5O3纳米晶体。采用XRD、SEM及EDS对产物的晶相、形貌和成分进行了分析,对Ba0.8Sr0.2Ti0.5Mn0.5O3制作的电极进行了气敏性质的测定。     

Studies on photodegradation of two commercial dyes in aqueous phase using different photocatalysts

The present study involves the photocatalytic degradation of Methyl Orange (MO) and Rhodamine 6G (R6G), employing heterogeneous photocatalytic process. Photocatalytic activity of various semiconductors such as titanium dioxide (TiO(2)), zinc oxide (ZnO), stannic oxide (SnO(2)), zinc sulphide (ZnS) and cadmium sulphide (CdS) has been investigated. An attempt has been made to study the effect of process parameters viz., amount of catalyst, concentration of dye and pH on photocatalytic degradation of MO and R6G. The experiments were carried out by irradiating the aqueous solutions of dyes containing photocatalysts with UV and solar light. The rate of decolorization was estimated from residual concentration spectrophotometrically. Similar experiments were carried out by varying pH (2-10), amount of catalyst (0.25-2.0g/l) and initial concentration of dye (5-200mg/l). The experimental results indicated that the maximum decolorization (more than 90%) of dyes occurred with ZnO catalyst and at basic pH and the maximum adsorption of MO was noticed at pH 4 and of R6G at pH 10. The percentage reduction of MO and R6G was estimated under UV/solar system and it was found that COD reduction takes place at a faster rate under solar light as compared to UV light. In case of R6G, highest decolorizing efficiency was achieved with lower dose of catalyst (0.5g/l) than MO (1g/l) under similar conditions. The performance of photocatalytic system employing ZnO/solar light was observed to be better than ZnO/UV system.     

The decolorization and mineralization of acid orange 6 azo dye in aqueous solution by advanced oxidation processes: a comparative study

The comparison of different advanced oxidation processes (AOPs), i.e. ultraviolet (UV)/TiO(2), O(3), O(3)/UV, O(3)/UV/TiO(2), Fenton and electrocoagulation (EC), is of interest to determine the best removal performance for the destruction of the target compound in an Acid Orange 6 (AO6) solution, exploring the most efficient experimental conditions as well; on the other hand, the results may provide baseline information of the combination of different AOPs in treating industrial wastewater. The following conclusions can be drawn: (1) in the effects of individual and combined ozonation and photocatalytic UV irradiation, both O(3)/UV and O(3)/UV/TiO(2) processes exhibit remarkable TOC removal capability that can achieve a 65% removal efficiency at pH 7 and O(3) dose=45mg/L; (2) the optimum pH and ratio of [H(2)O(2)]/[Fe(2+)] found for the Fenton process, are pH 4 and [H(2)O(2)]/[Fe(2+)]=6.58. The optimum [H(2)O(2)] and [Fe(2+)] under the same HF value are 58.82 and 8.93mM, respectively; (3) the optimum applied voltage found in the EC experiment is 80V, and the initial pH will affect the AO6 and TOC removal rates in that acidic conditions may be favorable for a higher removal rate; (4) the AO6 decolorization rate ranking was obtained in the order of O(3)相似文献   

Adsorption and photocatalytic decolorization of a synthetic dye erythrosine on anatase TiO2 and ZnO surfaces

The UV radiation assisted photocatalytic decolorization/degradation kinetics of an anionic dye erythrosine (ER), has been studied over TiO2 and ZnO surfaces. Since adsorption is the prerequisite condition for decolorization/degradation of dye molecules in presence of heterogeneous catalysis, the Langmuir and Freundlich isotherms were examined to verify the adsorption intensity. Standard adsorption free energy measurement implies that the adsorption of ER on both TiO2 and ZnO surfaces is spontaneous endothermic process. The effect of catalyst loading (TiO2/ZnO) revealed the fact that the maximum decolorization rate is obtained under an optimized catalyst loading condition. The decolorization efficiency was also investigated over the pH range of 5.0-10.0 indicating that increasing pH enhances decolorization efficiency. The influence of H2O2 on decolorization efficiency was found noticeable since it is a hydroxyl radical provider. The kinetic study of this degradation indicates that under the experimental condition, the decolorization mechanism follows zero order kinetics on the basis of Langmuir-Hinshelwood (L-H) heterogeneous reaction mechanism.     

Kinetics of decolorization of an azo dye in UV alone and UV/H(2)O(2) processes

The decolorization of C.I. Acid Red 27 (AR27), a monoazo anionic dye, was studied in the ultraviolet radiation (UV) alone and UV plus hydrogen peroxide (UV/H(2)O(2)) processes. The experimental results indicated that the kinetics of both oxidation processes fit well by pseudo-first order kinetics. The reaction rate was sensitive to the operational parameters and increased with increasing H(2)O(2) concentration and light intensity. The reaction orders of H(2)O(2) concentration and light intensity in both processes were obtained with linear regression method. A regression model was developed for pseudo-first order rate constant (k(ap,UV/H(2)O(2))) as a function of the Cconcentration and UV light intensity. (k(ap,UV/H(2)O(2)))=(2 x 10(-4)I(0.75)(0) + k(3)I(1.38)(0)[H(2)O(2)](n)(0))phi(AR27). As a result of two opposing effects of H(2)O(2) concentration at low and high concentrations, n has a value of 0.49 and -0.39 and k(3) has a value of 3 x 10(-4) and 0.1 for the regions of 0 mg l(-1) < [H(2)O(2)](0) < 650 mg l(-1) and 650 mg l(-1) < [H(2)O(2)](0) < 1500 mg l(-1)1, respectively. PhiAR27 is the initial dye concentration correlation index for developing of model for different initial concentrations of AR27. This rate expression can be used for predicting k(ap,UV/H(2)O(2) at different conditions in UV alone and UV/H2O2 processes. The results show that UV alone cannot be an efficient method for decolorization of AR27 in comparison with UV/H(2)O(2) process, therefore the first term of the model can be neglected.     

Prevenient dye-degradation mechanisms using UV/TiO2/carbon nanotubes process

Photocatalysis research heavily emphasizes increasing photo-efficiency. This study presents the application of carbon nanotubes (CNTs) to increase the photocatalytic activity of TiO(2). It elucidates the effect of CNTs dose on the decolorization efficiency of aqueous azo dye, C.I. Reactive Red 2 (RR2), determines the effects of SO(4)(2-) formation and removal of total organic carbon (TOC), and measures the effects of various ultraviolet wavelengths. Scanning electron microscopy was used to elucidate the mixing phenomenon and the size of TiO(2) and CNTs; X-ray diffraction was used to determine crystallinity; a BET meter was used to measure surface area and a spectrophotometry was used to determine the decolorization of RR2. Experimental results indicated significant effects of photodegradation on the combination of TiO(2) with CNTs and electron transfer is higher for 410 nm irradiation than for 365 nm, revealing that solar light can be used. The electron transfer in the TiO(2)/CNTs composites reduced the electron/hole recombination and increased the photon efficiency and the prevenient dye-degradation mechanisms using UV/TiO(2)/CNTs were established.     

Photocatalytic degradation of triazinic ring-containing azo dye (Reactive Red 198) by using immobilized TiO2 photoreactor: bench scale study

The decolorization and degradation of triazinic ring-containing azo dye by using TiO(2)-immobilized photoreactor is reported. A simple and easy method was used for the immobilization of photocatalyst. Reactive Red 198 (RR 198) was used as model compound. Photocatalytic degradation processes were performed using a 5 L (bench scale) solution containing dye. Batch mode immersion type method was used for the treatment of dye solution. UV-vis, ion chromatography (IC) and chemical oxygen demand (COD) analyses were employed to evaluate the results of the photocatalytic degradation of RR 198. Dye solution was completely decolorized in relatively short time (35 min) after UV irradiation in combination with hydrogen peroxide. The results verified that all of the dye molecules were destructed. Kinetics analysis indicates that the dye photocatalytic decolorization rates followed first order model (R(2) = 0.99). Ion chromatography analysis was used to investigate the formation and destruction of aliphatic carboxylic acids and formation of inorganic anions during the process. Formate and oxalate anions were detected as main aliphatic carboxylic intermediates, which were further oxidized slowly to CO(2). UV/TiO(2)/H(2)O(2) process proved to be capable of successful decolorization and degradation of the RR 198.     

Decolorization of alkaline TNT hydrolysis effluents using UV/H(2)O(2)

Effects of H(2)O(2) dosage (0, 10, 50, 100 and 300 mg/l), reaction pH (11.9, 6.5 and 2.5) and initial color intensity (85, 80 and 60 color unit) on decolorization of alkaline 2,4,6-trinitrotoluene (TNT) hydrolysis effluents were investigated at a fixed UV strength (40 W/m(2)). Results indicated that UV/H(2)O(2) oxidation could efficiently achieve decolorization and further mineralization. Pseudo first-order decolorization rate constants, k, ranged between 2.9 and 5.4 h(-1) with higher values for lower H(2)O(2) dosage (i.e., 10 mg/l H(2)O(2)) when the decolorization occurred at the reaction pH of 11.9, whereas a faster decolorization was achieved with increase in H(2)O(2) dosage at both pH 6.5 and 2.5, resulting in the values of k as fast as 15.4 and 26.6 h(-1) with 300 mg/l H(2)O(2) at pH 6.5 and 2.5, respectively. Difference in decolorization rates was attributed to the reaction pH rather than to the initial color intensity, resulting from the scavenging of hydroxyl radical by carbonate ion. About 40% of spontaneous mineralization was achieved with addition of 10 mg/l H(2)O(2) at pH 6.5. Efficient decolorization and extension of H(2)O(2) longevity were observed at pH 6.5 conditions. It is recommended that the colored effluents from alkaline TNT hydrolysis be neutralized prior to a decolorization step.     

Structural in situ study of the thermal behavior of manganese dioxide materials: toward selected electrode materials for supercapacitors

The thermal behavior of a series of MnO2 materials was investigated toward MnO2 microstructures under inert atmospheres. The byproduct formed during MnO2 heat treatments from the room temperature to 800 °C were characterized by in situ X-ray diffraction analyses. It was found that annealing spinel and ramsdellite phases caused the formation of MnO2 pyrolusite at 200 °C, Mn2O3, at 400 °C, and then Mn3O4 at higher temperatures. In the case of cryptomelane and birnessite phases, the heating process resulted in the formation of K0.51Mn0.93O2 at 600 °C, while Mn3O4 was also formed and still present up to 800 °C. Heat-treating Ni-todorokite and OMS-5 up to about 450 °C led to the formation of NiMn2O4 and NaxMnO2, respectively, and again Mn3O4 at higher temperatures. All of these structural transformations were correlated to resulting weight losses of MnO2 powders, measured by thermogravimetric analyses, during the heating process. Cyclic voltammetry measurements were performed in the presence of 0.5 M K2SO4 aqueous solution for annealed cryptomelane, K0.51Mn0.93O2, and Mn3O4-based electrodes. It was found that MnO2 cryptomelane is electrochemically stable upon heating. The long-term charge/discharge voltammetric cycling revealed that the specific capacitance of Mn3O4-based electrode is significantly improved from 14 F·g(-1) (after 20 cycles) to 123 F·g(-1) (after 500 cycles).     

Decolorization kinetics of Procion H-exl dyes from textile dyeing using Fenton-like reactions

The decolorization kinetics of three commercially used Procion H-exl dyes was studied using a Fenton-like reagent. The effect of the major system parameters (pH, concentration of H(2)O(2) and Fe(3+) and initial dye concentration) on the kinetics was determined. For comparison, the effect of the use of UV irradiated Fenton-like reagent and of Fenton reagent on the kinetics was also examined. In addition, mineralization rates and the biodegradability improvement as well as the effect of the addition of Cl(-), CO(3)(2-) or HCO(3)(-) on the decolorization rates was studied. The reactions were carried out in a 300 ml stirred cylindrical reactor with the capability of UV irradiation. The dye half-life time goes through a minimum with respect to the solution pH between 3 and 4. It also exhibits a broad minimum with respect to Fe(3+) and H(2)O(2) at molar ratios of H(2)O(2)/Fe(3+) from about 100 to 10. The addition of CO(3)(2-) and HCO(3)(-) substantially reduces the decolorization rates, while this effect is significantly less pronounced with Cl(-). At an optimum range of parameters, the mineralization rate (TOC reduction) is very slow for the Fenton-like process (TOC decrease from an initial 49.5 to 41.1 mg/l after 30 min and to only 35.2 mg/l after 600 min), but it increases significantly for the photo-Fenton-like process (to TOC values of 39.7 and 11.4 mg/l, respectively). The biodegradability, as expressed by the BOD/COD ratio, increases significantly from an initial value of 0.11-0.55 for the Fenton-like and to 0.72 for the photo-Fenton-like processes.     

Comparison of the treatment methods efficiency for decolorization and mineralization of Reactive Black 5 azo dye

Degradation of Reactive Black 5 (RB5), a well-known non-biodegradable disazo dye, has been studied using UV/TiO2, wet-air oxidation (WAO), electro-Fenton (EF) and UV/electro-Fenton (UV/EF) advanced oxidation processes (AOPs). The efficiency of substrate decolorization and mineralization in each process has been comparatively discussed by decreases in concentration and total organic carbon content of RB5 solutions. The most efficient method on decolorization and mineralization was observed to be WAO process. Mineralization efficiency was observed in the order of WAO>UV/TiO2>UV/EF>EF. Final solutions of AOPs applications after 90 min treatment can be disposed safely to environment. Photocatalytic degradation kinetics of RB5 successfully fitted to Langmuir-Hinshelwood (L-H) kinetics model. The values of second order degradation rate constant (k') and adsorption constant (K) were determined as 5.085 mg L(-1)min(-1) and 0.112 L mg(-1), respectively.     

An integrated technique using zero-valent iron and UV/H2O2 sequential process for complete decolorization and mineralization of C.I. Acid Black 24 wastewater

The zero-valent iron (ZVI) reduction succeeds for decolorization, while UV/H(2)O(2) oxidation process results into mineralization, so that this study proposed an integrated technique by reduction coupling with oxidation process in order to acquire simultaneously complete both decolorization and mineralization of C.I. Acid Black 24. From the experimental data, the zero-valent iron addition alone can decolorize the dye wastewater yet it demanded longer time than ZVI coupled with UV/H(2)O(2) processes (Red-Ox). Moreover, it resulted into only about 30% removal of the total organic carbon (TOC), which was capable to be effectively mineralized by UV/H(2)O(2) process. The proposed sequential ZVI-UV/H(2)O(2) integration system cannot only effectively remove color and TOC in AB 24 wastewater simultaneously but also save irradiation power and time demand. Furthermore, the decolorization rate constants were about 3.77-4.0 times magnitude comparing with that by UV/H(2)O(2) process alone.